<!DOCTYPE HTML>
<html> 
<head>
<script language="javascript">
function draw(){
    var ctx = document.getElementById('myCanvas').getContext('2d');
    for (var i=1;i<10;i++){   
        ctx.strokeStyle = 'blue';
        ctx.lineWidth = 10;
        ctx.lineJoin = 'miter';
        ctx.miterLimit = i*10;
        ctx.beginPath();
        ctx.moveTo(10,i*30);
        ctx.lineTo(100,i*30);
        ctx.lineTo(10,33*i);
        ctx.stroke();
    }
}
window.onload=function(){
    draw();
}
</script>
</head>
<body>
<canvas id="myCanvas" width="1600" height="300"></canvas>
</body>
</html>
